It has been proposed that an anisotropic conductive film including an insulating adhesive composition in which conductive particles containing a resin core and a nickel/gold plated layer formed on the surface of the resin core, and the like, are dispersed is used when mounting an IC chip on a substrate (Patent Literature 1). In this case, the conductive particles are squeezed between a terminal of the IC chip and a terminal of the substrate, or dig into the respective terminals thereby to ensure conduction, and the insulating adhesive composition fixes the IC chip, the substrate, and the conductive particles.
However, the conductive particles do not form a metal bond between the terminal of the IC chip and the terminal of the substrate. Therefore, there has been a problem that, when a connection structure obtained by connecting the IC chip to the substrate through the anisotropic conductive film is stored in a high-temperature and high-humidity environment, conduction reliability decreases.
To address this problem, it is considered to adopt, as conducive particles for an anisotropic conductive film, solder particles which form a metal bond with copper or the like at a temperature that is relatively low compared to metal such as copper and aluminum generally used as a terminal material of an IC chip.